Free JavaScript Formatter — Beautify & Unminify JS
Beautify and unminify JavaScript with consistent indentation. Arrow functions, async/await, and modules supported.
Quick answer
To format JavaScript, paste your code into the KaviForge JavaScript Formatter. It is beautified instantly with consistent indentation, line breaks, and spacing. Minified bundles become readable again. Choose 2 spaces, 4 spaces, or tabs.
Beautify or unminify JavaScript in your browser. Restore readable structure to minified bundles and keep modern ES syntax intact.
The formatter understands modern JavaScript — arrow functions, classes, async/await, destructuring, spread, optional chaining, and template literals.
Related reading: A Simple Guide to Parsing JSON in JavaScript (ES6+), 5 Reasons to Use an Online Formatter (Instead of Your IDE), and How to Minify JSON (and Why It Makes Your Site Faster).
How to Format JavaScript
- 1Paste your JavaScript into the input box, or upload a .js file.
- 2Choose the indentation style.
- 3Read the formatted code in the output box as you type.
- 4Use "Use as input" to continue editing the formatted result.
- 5Copy the code or download it as formatted.js.
Features
Beautify & Unminify
Expands minified one-line code into readable, indented blocks.
Modern Syntax
Handles ES2015–ES2024 features including async/await and optional chaining.
Preserves Blank Lines
Keeps intentional spacing between logical sections (up to 2 lines).
Indentation Choice
2 spaces, 4 spaces, or tabs.
File Upload & Download
Open .js, .mjs, .jsx, or .json files and save the result.
Private
Your source code is never uploaded.
When to Use the JavaScript Formatter
Debug production bundles
Unminify a stack-trace file to understand what the code is doing.
Review third-party scripts
Inspect analytics, widget, or ad scripts before adding them to your site.
Tidy snippets for sharing
Format code for blog posts, documentation, and support tickets.
Quick formatting without tooling
Format code on any machine without installing Prettier or an IDE.
About the JavaScript Formatter
Formatting uses js-beautify’s JavaScript beautifier, loaded only when you use the tool. It reformats whitespace and line breaks without changing how your code runs.
Formatting does not reverse obfuscation: renamed variables such as a, b, and c stay as they are. The formatter also does not check for syntax errors.
JavaScript Formatter FAQs
How do I unminify JavaScript?
Paste the minified code into the KaviForge JavaScript Formatter. It is expanded into readable, indented code instantly.
Does formatting change how my code works?
No. Only whitespace and line breaks change; the code behaves exactly the same.
Can this deobfuscate JavaScript?
It makes obfuscated code readable by formatting it, but it cannot restore original variable names or undo string encoding.
Does it support TypeScript or JSX?
Simple TypeScript and JSX often format acceptably, but the formatter is designed for JavaScript. For full TypeScript support use Prettier in your editor.
Does it validate JavaScript syntax?
No. It reformats the code as written. Use your browser console or a linter to find syntax errors.
Is my code uploaded?
No. All formatting happens in your browser.
Related Developer Tools
JSON Formatter & Validator
Pretty print, beautify, minify, and validate JSON online free. Tree view, file upload, private browser-only.
HTML Formatter
Beautify messy or minified HTML with clean indentation, or minify it for production. Free and private.
CSS Formatter
Beautify minified CSS into readable rules, or minify CSS to reduce file size. Runs in your browser.
Related Guides & Tutorials
A Simple Guide to Parsing JSON in JavaScript (ES6+)
Parse a JSON payload in JavaScript with JSON.parse() and ES6+. See examples, then pretty print or minify JSON with our free online tool.
5 Reasons to Use an Online Formatter (Instead of Your IDE)
Why an online JSON formatter beats your IDE for a quick JSON payload. Pretty print or minify JSON instantly — no setup, no signup.
How to Minify JSON (and Why It Makes Your Site Faster)
Learn how to minify JSON to shrink payloads and speed up APIs. Use the free minifier — minify JSON in your browser in one click.